1. Field of the Invention
The present invention relates to an ultrasonic treatment system including an ultrasonic treatment instrument to conduct a treatment by use of an ultrasonic vibration, and an energy source unit which supplies an electric power to actuate the ultrasonic treatment instrument, an energy source unit which supplies electric an electric power to actuate an ultrasonic treatment instrument, and an actuation method of an energy source unit.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2005-27907 discloses an ultrasonic treatment system configured to transmit an ultrasonic vibration generated in an ultrasonic transducer to an ultrasonic probe, and configured to conduct a treatment with a treatment portion provided in a distal end of the ultrasonic probe. This ultrasonic treatment system detects an ultrasonic impedance on the basis of an electric power supplied to the ultrasonic transducer while the ultrasonic vibration is being generated in the ultrasonic transducer. The ultrasonic impedance changes in response to a load on the ultrasonic probe. When the electric power is supplied to the ultrasonic transducer, the ultrasonic impedance is compared with a set threshold (upper limit impedance). If the ultrasonic impedance becomes higher than the threshold, an electric current (the crest value of an alternating electric current) supplied to the ultrasonic transducer is reduced. Thus, the amplitude of the ultrasonic vibration (longitudinal vibration) generated in the ultrasonic transducer decreases.